Add support for dynamic discrete spaces by quaquel · Pull Request #2755 · mesa/mesa

quaquel · 2025-04-14T17:55:26Z

Currently, all DiscreteSpace subclasses rely on @cache and @cached_property for neighborhood-related functionality. This is critical for performance. However, if you want to represent a dynamically changing discrete space (e.g., a dynamic network), this is currently not possible. See ##2754 for more details

API

This PR adds explicit support for changing discrete spaces during the simulation. It adds 4 new methods to DiscreteSpace which means these are available to all subclasses. These methods are add_cell, remove_cell, add_connection, remove_connection. With these, you can make any modification to a discrete space that you want. For example, it allows you to dynamically change a network or impose a barrier in an orthogonal grid by removing connections between specific cells.

Implementation details

This adds support for adding and removing cells and connections to discrete spaces. The critical issue is that discrete spaces relies on caching neighborhoods for substantial performance gains. Cell already has a connect and disconnect method, so clearing the relevant cell caches is placed here. The new methods (add_cell, remove_cell, add_connection, remove_connection) are added to DiscreteSpace, and the relevant cache (all_cells) is cleared here as well.

The clearing of caches on connect and disconnect adds some additional overhead when constructing a discrete space. It might be possible to reduce this overhead by checking if the cache is already active (long story short, this can be done by checking if self.__dict__["name of cached property"] exists, but this adds code complexity).

for more information, see https://pre-commit.ci

coderabbitai · 2025-04-14T17:55:34Z

Important

Review skipped

Auto reviews are disabled on this repository.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

Review comments: Directly reply to a review comment made by CodeRabbit. Example:
- I pushed a fix in commit <commit_id>, please review it.
- Generate unit testing code for this file.
- Open a follow-up GitHub issue for this discussion.
Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
- @coderabbitai generate unit testing code for this file.
- @coderabbitai modularize this function.
PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
- @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
- @coderabbitai read src/utils.ts and generate unit testing code.
- @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
- @coderabbitai help me debug CodeRabbit configuration file.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

@coderabbitai pause to pause the reviews on a PR.
@coderabbitai resume to resume the paused reviews.
@coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
@coderabbitai full review to do a full review from scratch and review all the files again.
@coderabbitai summary to regenerate the summary of the PR.
@coderabbitai generate docstrings to generate docstrings for this PR.
@coderabbitai resolve resolve all the CodeRabbit review comments.
@coderabbitai configuration to show the current CodeRabbit configuration for the repository.
@coderabbitai help to get help.

Other keywords and placeholders

Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit Configuration File (`.coderabbit.yaml`)

You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
Please see the configuration documentation for more information.
If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

Visit our Documentation for detailed information on how to use CodeRabbit.
Join our Discord Community to get help, request features, and share feedback.
Follow us on X/Twitter for updates and announcements.

for more information, see https://pre-commit.ci

github-actions · 2025-04-14T18:03:38Z

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
BoltzmannWealth	small	🔴 +29.6% [+28.5%, +30.7%]	🔵 +0.5% [+0.3%, +0.6%]
BoltzmannWealth	large	🔴 +36.1% [+17.7%, +45.5%]	🔵 +0.8% [+0.0%, +1.4%]
Schelling	small	🔴 +55.1% [+54.8%, +55.4%]	🔵 +0.3% [+0.1%, +0.5%]
Schelling	large	🔴 +58.0% [+55.5%, +61.2%]	🔵 -1.5% [-2.0%, -1.0%]
WolfSheep	small	🔴 +24.7% [+24.2%, +25.3%]	🔵 -0.3% [-0.5%, -0.1%]
WolfSheep	large	🔴 +27.8% [+27.3%, +28.2%]	🔴 +4.5% [+3.6%, +5.4%]
BoidFlockers	small	🔵 +1.6% [+1.1%, +2.1%]	🔵 -0.8% [-1.0%, -0.6%]
BoidFlockers	large	🔵 +1.3% [+0.9%, +1.7%]	🔵 -0.5% [-0.7%, -0.2%]

quaquel · 2025-04-14T18:05:52Z

The increase in init_time is due to the clearing of non-existing caches on all cell.connect calls when instantiating the spaces. It's possible to resolve this but the numbers or tiny and it adds code complexity if we want to do that.

for more information, see https://pre-commit.ci

mesa/discrete_space/discrete_space.py

for more information, see https://pre-commit.ci

Sahil-Chhoker · 2025-04-16T18:09:57Z

The increase in init_time is due to the clearing of non-existing caches on all cell.connect calls when instantiating the spaces. It's possible to resolve this but the numbers or tiny and it adds code complexity if we want to do that.

I am not asking for the complete implementation, but can you give me just a initial idea of how can the init time be reduced?

quaquel · 2025-04-16T18:13:34Z

I am not asking for the complete implementation, but can you give me just a initial idea of how can the init time be reduced?

In Cell, there are 3 places were caching happens: neighborhood, _neighborhood, and get_neighborhood. These are tied together with neighborhood as the basis. neighborhood is a cached property. The cached value is stored in self.__dict__["neighborhood"]. So, if this field thas not exist, the other caches also won't exist and thus won't have to be cleared. No idea how much runtime it would save.

Sahil-Chhoker · 2025-04-16T18:16:26Z

But won't that eliminate the caching entirely from cell?

quaquel · 2025-04-16T18:32:00Z

No, but why do you think that it might?

EwoutH

This is really cool, and a remarkably clean PR!

Sahil-Chhoker · 2025-04-16T20:27:32Z

No, but why do you think that it might?

I am not sure about the current structure, I will do some individual research later. Thanks again for these discussions, learning a lot from these.

tpike3

This is great, I think we can worry about decreasing the init later. I know we have at least one user who needs this functionality.

quaquel · 2025-04-17T14:08:35Z

I'll expand the docstrings a bit more probably tomorrow and merge this afterwards.

for more information, see https://pre-commit.ci

github-actions · 2025-04-20T07:44:50Z

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
BoltzmannWealth	small	🔴 +30.6% [+28.8%, +32.6%]	🔵 +0.0% [-0.2%, +0.2%]
BoltzmannWealth	large	🔴 +57.3% [+38.1%, +93.7%]	🔵 -4.1% [-6.1%, -2.0%]
Schelling	small	🔴 +48.4% [+48.0%, +48.8%]	🔵 +0.3% [-0.0%, +0.6%]
Schelling	large	🔴 +42.0% [+34.4%, +46.6%]	🔵 -2.6% [-5.7%, +0.1%]
WolfSheep	small	🔴 +18.7% [+18.3%, +19.1%]	🔵 -0.5% [-0.8%, -0.3%]
WolfSheep	large	🔴 +19.8% [+19.1%, +20.5%]	🟢 -5.3% [-7.1%, -3.6%]
BoidFlockers	small	🔵 -1.9% [-2.6%, -1.2%]	🔵 +0.2% [+0.1%, +0.3%]
BoidFlockers	large	🔵 -0.7% [-1.2%, -0.3%]	🔵 +0.3% [+0.0%, +0.5%]

quaquel and others added 2 commits April 14, 2025 19:49

initial commit

8b7b37b

[pre-commit.ci] auto fixes from pre-commit.com hooks

0abf697

for more information, see https://pre-commit.ci

quaquel and others added 2 commits April 14, 2025 19:58

Update network.py

58e23f1

[pre-commit.ci] auto fixes from pre-commit.com hooks

63617d4

for more information, see https://pre-commit.ci

quaquel added the enhancement Release notes label label Apr 14, 2025

quaquel linked an issue Apr 14, 2025 that may be closed by this pull request

Dynamic Discrete Spaces #2754

Closed

quaquel and others added 2 commits April 14, 2025 20:15

docstrings

ce726ff

[pre-commit.ci] auto fixes from pre-commit.com hooks

abcb32a

for more information, see https://pre-commit.ci

quaquel mentioned this pull request Apr 14, 2025

Dynamic Discrete Spaces #2754

Closed

quaquel and others added 2 commits April 14, 2025 20:35

extra comment

90eaf6e

[pre-commit.ci] auto fixes from pre-commit.com hooks

9d0d754

for more information, see https://pre-commit.ci

Sahil-Chhoker reviewed Apr 15, 2025

View reviewed changes

mesa/discrete_space/discrete_space.py Outdated Show resolved Hide resolved

quaquel and others added 3 commits April 15, 2025 08:02

Update discrete_space.py

c7207fa

add unit tests

ab515a1

[pre-commit.ci] auto fixes from pre-commit.com hooks

f723455

for more information, see https://pre-commit.ci

quaquel requested review from Corvince, EwoutH and Sahil-Chhoker April 16, 2025 17:41

quaquel and others added 5 commits April 16, 2025 19:45

Update test_discrete_space.py

7ebe48f

Update test_discrete_space.py

23aefef

Update test_discrete_space.py

46b70a8

Update test_discrete_space.py

cff94c9

[pre-commit.ci] auto fixes from pre-commit.com hooks

9543125

for more information, see https://pre-commit.ci

EwoutH approved these changes Apr 16, 2025

View reviewed changes

tpike3 approved these changes Apr 17, 2025

View reviewed changes

quaquel and others added 2 commits April 20, 2025 09:35

minor cleanup

e5c2c0c

[pre-commit.ci] auto fixes from pre-commit.com hooks

c4a444c

for more information, see https://pre-commit.ci

quaquel added the trigger-benchmarks Special label that triggers the benchmarking CI label Apr 20, 2025

quaquel merged commit a62f75e into mesa:main Apr 20, 2025
13 checks passed

quaquel removed the trigger-benchmarks Special label that triggers the benchmarking CI label Apr 20, 2025

quaquel deleted the dynamic_discretespace branch December 30, 2025 09:41

Uh oh!

Conversation

quaquel commented Apr 14, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

API

Implementation details

Uh oh!

coderabbitai bot commented Apr 14, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Review skipped

Chat

CodeRabbit Commands (Invoked using PR comments)

Other keywords and placeholders

CodeRabbit Configuration File (.coderabbit.yaml)

Documentation and Community

Uh oh!

github-actions bot commented Apr 14, 2025

Uh oh!

quaquel commented Apr 14, 2025

Uh oh!

Uh oh!

Sahil-Chhoker commented Apr 16, 2025

Uh oh!

quaquel commented Apr 16, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Sahil-Chhoker commented Apr 16, 2025

Uh oh!

quaquel commented Apr 16, 2025

Uh oh!

EwoutH left a comment

Choose a reason for hiding this comment

Uh oh!

Sahil-Chhoker commented Apr 16, 2025

Uh oh!

tpike3 left a comment

Choose a reason for hiding this comment

Uh oh!

quaquel commented Apr 17, 2025

Uh oh!

github-actions bot commented Apr 20, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

quaquel commented Apr 14, 2025 •

edited

Loading

coderabbitai bot commented Apr 14, 2025 •

edited

Loading

CodeRabbit Configuration File (`.coderabbit.yaml`)

quaquel commented Apr 16, 2025 •

edited

Loading